dishwasher "rust" spots

lkswan747

lkswan747

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My LG Dishwasher has started leaving what looks like rust spots on our cutlery and other stainless steel utensils.
There are no alarm lights for salt, rinse aid or detergent. This issue does not happen on every wash cycle and seems to be more prevalent when I do not top the rinse aid to the top despite not showing a low status!
Does anyone have any advice as to what could be causing this.
 
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lkswan747 said:
My LG Dishwasher has started leaving what looks like rust spots on our cutlery and other stainless steel utensils.
There are no alarm lights for salt, rinse aid or detergent. This issue does not happen on every wash cycle and seems to be more prevalent when I do not top the rinse aid to the top despite not showing a low status!
Does anyone have any advice as to what could be causing this.
Click to expand...

I dont use salt or rinse aid ... never seen this :unsure:
 
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More than likely something to do with your drying cycle not working properly and therefore the moisture is oxidising.

So it’s actual rust. Could also relate to what your cutlery is made of.

Try opening the door the moment the dishwasher finishes so it can dry more quickly.
 
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it's very common, mine does this. You just have to rub the effing knives to get that little rust spot off, it's probably not even rust it's just some other oxidation etc. who knows. I suppose I could test my water hardness and all that, but yeah no... lol. And do you live at the coast etc?

use plastic cutlery and paper plates, problem solved :ROFL:
 
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The salt in the dishwasher is for soft water. The theory is that the salt helps soften the water, but salt can also be the cause of the rust. Its makes the wash more conductive, and iron ions ... from whatever is in or has been in the washer ... can cause oxidation. Rust.

Of course, no salt may cause scale on your glassware, depending on how hard your water is. Hard water isnt great for the detergent or scale.

In textile wet processing .... dyeing machines are like big dishwashers in a way, but we steer clear of common salt because its an oxidant and rather use glaubers salt, sodium sulphate, as its easier on the machines and better for cleaning. But of course, the water used in dyeing is softened prior to dyeing. But salt is a thing.....
We also use acetic acid as both an alkali neutralizer and to flush iron oxides. Iron IV oxide is a fabric killer, especially nylons.

What you could try, is to add some white vinegar instead of rinse aid for a wash or two. The vinegar will help to make the iron ions soluble, so counteracting the rust caused by the salt.
In SA, I used the vinegar when we had a scale build up on our glasses ... and it worked for me.
 
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Another thought ..... SA still has quite a few galvanized pipes and pipe fittings about.
Maybe there is a pipe or a fitting in your plumbing?
 
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Ive seen small rust spots on steak knives but never on normal knives and forks.

The normal knives are polished (smooth and shiny from factory) while the steak knives have been roughed up, i think this has something to do with it, or is just low grade stainless steel.
 
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Rickster said:
Ive seen small rust spots on steak knives but never on normal knives and forks.

The normal knives are polished (smooth and shiny from factory) while the steak knives have been roughed up, i think this has something to do with it, or is just low grade stainless steel.
Click to expand...

I think the multiple bevels in the serrations of steak knives probably also comes into play there.

If you have a “tray” style dishwasher putting them in with the blades up helps a lot with this.
 
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